title: Detection of autoinducer-2 and analysis of the profile of luxS and pfs transcription in Streptococcus suis serotype 2.
abstract: The only quorum sensing (QS) system shared by Gram-positive and Gram-negative bacteria involves the production of autoinducer-2 (AI-2). However, there have been no reports concerning the AI-2 in Streptococcus suis serotype 2 (SS2). In this study, we investigated AI-2 production and analyzed the relationship between the transcription level of luxS and pfs and AI-2 production. A homologue of luxS, the gene required for AI-2 synthesis in Vibrio harveyi, was isolated from the SS2 genome. V. harveyi BB170 bioassay demonstrated luxS functionality in SS2 and its ability to complement the luxS-negative phenotype of Escherichia coli DH5alpha. Further studies showed that AI-2 activity peaked in the late exponential phase, and sodium chloride or glucose increased the production of AI-2. Real-time PCR showed that the level of transcription of pfs is highly correlated with the level of AI-2 production, while the level of transcription of luxS does not correlate with the level of AI-2 production. The results presented here demonstrate that SS2 can secrete AI-2 and that the profile of pfs transcription is highly correlated with the level of AI-2 production.
authors.affiliation: Key Lab Animal Disease Diagnostic & Immunology, Ministry of Agriculture, Nanjing Agricultural University, Nanjing, China.
authors.forename: X G
authors.initials: XG
authors.lastname: Han
authors.forename: C P
authors.initials: CP
authors.lastname: Lu
mesh_terms: D001426:Bacterial Proteins / Q000235:genetics* / Q000378:metabolism; D013437:Carbon-Sulfur Lyases / Q000235:genetics* / Q000378:metabolism; D015964:Gene Expression Regulation, Bacterial; D006714:Homoserine / Q000031:analogs & derivatives* / Q000378:metabolism; D007783:Lactones / Q000378:metabolism*; D009699:N-Glycosyl Hydrolases / Q000235:genetics* / Q000378:metabolism; D017011:Streptococcus suis / Q000235:genetics* / Q000254:growth & development / Q000378:metabolism; D014158:Transcription, Genetic
chemical_list: D001426:Bacterial Proteins; D007783:Lactones; C091088:N-octanoylhomoserine lactone; D006714:Homoserine; D009699:N-Glycosyl Hydrolases; C019606:adenosylhomocysteine nucleosidase; D013437:Carbon-Sulfur Lyases; C117753:LuxS protein, Bacteria